Enantioselective synthesis of C(9) hydroxy analogues of hederacines A and B

Abstract A strategy for assembling the 5-7-5 fused ring system of the hederacine alkaloids is reported, based on a sequence of electrocyclic ring expansion, with trapping in situ, then Heck cyclisation. Subsequent furan oxidative N-cyclisation generates the azabicyclo[3.2.1]octane core, resulting in a synthesis of C(9) hydroxy analogues of hederacines A and B in 19 and 20 steps, respectively, from 2-methylcyclopentane-1,3-dione.